Sightings

Right whale sightings off the South Carolina coast:2011-12: 42 whales, 4 cow/calf pairs 2010-11: 36 whales, 5 cow/calf pairs2009-10: 55 whales, 19 cow/calf pairs2008-09: 121 whales, 39 cow/calf pairs (record season)Sea to Shore Alliance, NOAA

Rare giants are back in the Lowcountry seas — 40-ton right whales.

The endangered species will be out there all winter, so boaters are urged to be cautious. As recently as two years ago, an aerial-survey team spotted one of the whales off Hilton Head Island with a gaping wound across its back from the propeller of a recreation-size boat.

Ship strikes are considered a leading threat to the 50-foot-long animals, said to be on the brink of extinction.

People tend to think something that big would be easily spotted, but it’s not so.

“Right whales are dark with no dorsal fin, and they often swim slowly at or just below the water’s surface,” said Barb Zoodsma, federal National Oceanic and Atmospheric Administration right whale recovery program coordinator in the Southeast. “Just a slight difference in the texture on the water’s surface is often the only clue that a whale is present.”

Each fall, females and at least a few males head south from their Great Banks feeding grounds to give birth and winter in warmer waters off the Southeast. Year to year, dozens are spotted in waters off South Carolina, some with newborn calves.

Their route is heavily trafficked, and a NOAA rule requires that large ships slow to half-speed within 23 miles of the coast in months when the whales are present.

Shipping companies have been cited for violations, including at least two ships operating off Charleston.

Right-whale sightings already have been reported off South Carolina and Georgia, said Allison Garrett of NOAA.

A Sea to Shore Alliance team flying out of Charleston is part of a network trying to keep track of the whales, partly so ships know when they are around.

It’s not an easy task. The Charleston team was scheduled to fly its first flight for the season today, but team leader Melanie White said weather might keep them grounded until early next week. The flights this year are paid for entirely by NOAA Fisheries.

Right whales were nearly wiped out by whalers in the 19th century. Only about 400 are known to exist today, so few that researchers consider every whale vital to the survival of the species.

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